The present invention relates to an arrangement for ventilation of a space in a passenger compartment of a vehicle to selectively take in or discharge heated or cooled air depending upon ambient conditions.
A known practice is to introduce fresh air into the passenger compartment of vehicles via an inlet in the front wall of the compartment whereby the fresh air passes over a heating element and/or cooling element and is heated or cooled, depending on the ambient temperature. Air from the passenger compartment is released via outlets arranged in the vehicle's doors or in a rear end of a cab of a truck. This means that air which has been heated or cooled is discharged, thereby further increasing the respective need for heating or cooling of the inlet air.
Modem diesel engines operate at very high efficiency, which means that the engine generates relatively little waste heat, which can be utilised for heating the passenger compartment. In some cases it has been necessary, in smaller vehicles such as private cars, to provide extra heating units to meet the passenger compartment heating requirement in low ambient temperatures.
It should also be noted that the cooling required at high ambient temperatures reduces not insubstantially the power available from the vehicle's engine.
U.S. Pat. No. 4,062,273 refers to a ventilation arrangement for a rail vehicle. This known ventilation arrangement includes outlet devices arranged in a lower portion of a passenger space of the rail vehicle and an outlet device which extends from the passenger space through the roof of the rail vehicle.